The present invention relates to a system, including methods and devices, utilizing wireless sensor devices and RFID (radio-frequency identification) transponders. Specifically, the present invention relates to a system incorporating novel devices and methods that enable point-of-use and on-demand commissioning of RFID transponder-equipped wireless sensors.
Radio-frequency identification (RFID) transponders enable improved identification and tracking of objects by encoding data electronically in a compact tag or label. And, advantageously, the compact tag or label does not need external, optically recognizable or human-readable markings. In fact, using the Gen2 EPC specification, a three-meter read-distance for RFID transponders is common—even on high-speed material handling lines.
Radio-frequency identification (RFID) transponders, typically thin transceivers that include an integrated circuit chip having radio frequency circuits, control logic, memory and an antenna structure mounted on a supporting substrate, enable vast amounts of information to be encoded and stored and have unique identification. Commissioning, the process of encoding specific information (for example, data representing an object identifier, the date-code, batch, customer name, origin, destination, quantity, and items) associated with an object (for example, a shipping container), associates a specific object with a unique RFID transponder. The commissioned transponder responds to coded RF signals and, therefore, readily can be interrogated by external devices to reveal the data associated with the transponder.
Current classes of RFID transponders rank into two primary categories: active RFID transponders and passive RFID transponders. Active RFID transponders include an integrated power source capable of self-generating signals, which may be used by other, remote reading devices to interpret the data associated with the transponder. Active transponders include batteries and, historically, are considered considerably more expensive than passive RFID transponders. Passive RFID transponders backscatter incident RF energy to specially designed remote devices such as interrogators.
Combining the benefits of the latest technology in RFID transponders with sensing devices, a broader class of devices called wireless sensors is emerging. Wireless sensors have a unique identity, sense one or more attributes within its environment, and report its identity and data corresponding to the sensed attributes. For example, a wireless sensor interprets environmental conditions such as temperature, moisture, sunlight, seismic activity, biological, chemical or nuclear materials, specific molecules, shock, vibration, location, or other environmental parameters. Wireless sensors are distributed nodes of computing networks that are interconnected by wired and wireless interfaces.
Wireless sensors, made using silicon circuits, polymer circuits, optical modulation indicia, an encoded quartz crystal diode, or Surface Acoustic Wave (SAW) materials to affect radio frequency or other signaling methods, communicate wirelessly to other devices. For example, certain embodiments of wireless sensors communicate on a peer-to-peer basis to an interrogator or a mobile computer. Communication methods include narrow band, wide band, ultra wide band, or other means of radio or signal propagation methods.
Additional examples of RFID transponders, wireless tags, and wireless sensors are more fully discussed in this inventor's co-pending U.S. Patent Application Publication No. 2006/0080819, entitled “Systems and Methods for Deployment and Recycling of RFID Tags, Wireless Sensors, and the Containers Attached thereto,” published on 20 Apr. 2006, which is incorporated by reference for all purposes in this document.
One problem of prior-art systems, such as conventional print labels or barcode systems, includes a requirement for line of sight and an overdependence on the optical quality of the label. Many factors can render such a label unreadable including printing errors, excess ink, insufficient ink, physical destruction of the markings, obstruction of the markings due to foreign matter, and, in extreme cases, outright deception by placing an altered label over the top of such a print label.
RFID transponder labeling eliminates the need for an optically readable print label and overcomes all of the shortcomings related to print quality and the need for line of sight to scan the label. Moreover, RFID transponder labels enable secure data encryption, making outright deception considerably less likely to occur. However, current RFID label systems have their own limitations as well.
For example, certain prior art systems, as represented by U.S. Pat. No. 7,066,667 issued to Chapman et al. on 27 Jun. 2006 and include U.S. Pat. No. 5,899,476 issued to Barrus et al. on 31 May 2005, or by U.S. Pat. No. 6,246,326 issued to Wiklof et al. on 12 Jun. 2001, describe a device that commissions an RFID transponder with a printed label. This approach, however, introduces unnecessary waste, cost, and propensities for error. There is a growing category of applications that do not require anything other than a custom-encoded RFID transponder. This prior art calls for the inclusion of label printer hardware and related consumable materials that are not necessary for many RFID applications. Unneeded printer mechanisms create unnecessary complexities, size, and weight. In some instances this additional bulk hinders practical mobile applications.
United States Patent Application No. 2003/0227528 by Hohberger et al. published on 11 Dec. 2003 describes another attempt at improving demand-print labels by providing a device that combines two standard, die-cut rolls of media, one of which may be a roll of RFID transponders, and the second, print-label stock, in an attempt to provide on-demand smart labels. As with the aforementioned references, this approach adds unnecessary cost and complexity by combining RFID transponders with demand-printed labels.
So, despite recent advances in RFID technology, the state-of-the-art does not fully address the needs of efficient, economical, high-volume, cost-effective, reliable deployment and commissioning of RFID transponders and wireless sensors. And, large-scale adoption and deployment of RFID transponders depends on systems utilizing reliable, low-cost transponders and efficient commissioning means. Such systems should further include compliance with Gen2 EPC specifications or ISO standards, enable a plurality of printer-emulation modes, enable wireless connectivity—for example, in accordance with the IEEE 802.11b wireless LAN standards-based communications—provide various levels of WLAN security, efficient replenishment of programmable transponder supplies, and enable secure software re-programming to adapt to future demands and improvements.